The present invention relates generally to methods for cancer diagnosis, and more particularly to the use of compounds that detect expression of OB-cadherin or N-cadherin for diagnosing and determining the metastatic potential of cancers such as breast, ovarian and prostate cancer, as well as leukemia.
Cancer is a significant health problem throughout the world. Although advances have been made in detection and therapy of cancer, no vaccine or other universally successful method for prevention or treatment is currently available. For example, among women, breast and ovarian cancer are prevalent in the United States and other countries. Breast cancer, in particular, remains the second leading cause of cancer-related deaths in women, affecting more than 180,000 women in the United States each year. For women in North America, the life-time odds of getting breast cancer are now one in eight. Management of the disease currently relies on a combination of early diagnosis (through routine breast screening procedures) and aggressive treatment, which may include one or more of a variety of treatments such as surgery, radiotherapy, chemotherapy and hormone therapy. The course of treatment for a particular breast cancer is often selected based on a variety of prognostic parameters, including an analysis of specific tumor markers. See, e.g., Porter-Jordan and Lippman, Breast Cancer 8:73-100, 1994. However, it remains difficult to evaluate the metastatic potential of a cancer, and the high mortality observed in breast cancer patients indicates that improvements are needed in the diagnosis and management of the disease.
Prostate cancer is the most common form of cancer among males, with an estimated incidence of 30% in men over the age of 50. Human prostate cancer has the propensity to metastasize to bone. Treatment is commonly based on surgery and/or radiation therapy, but these methods are ineffective in a significant percentage of cases, and this prevalent disease is currently the second leading cause of cancer death among men in the U.S. To improve treatment of the disease, early diagnosis is critical, but prostate cancer remains difficult to detect accurately. Two prostate specific proteins, prostate specific antigen (PSA) and prostatic acid phosphatase (PAP), have been used for diagnosis, but techniques employing such proteins cannot provide complete diagnostic information. For example, PSA measurements not indicate the level of metastasis of a prostate cancer.
Although additional markers for prostate and other cancers continue to be discovered, there is presently no accurate method for evaluating the metastatic potential of these cancers. In order to improve cancer treatment and survival, techniques that permit a more accurate diagnosis are needed. The present invention fulfills these needs and further provides other related advantages.
Briefly stated, this invention provides compositions and methods for diagnosing cancer, such as breast, ovarian and prostate cancer, as well as leukemia. Certain methods provided herein employ binding agents, such as antibodies and fragments thereof, that specifically recognize OB-cadherin or N-cadherin. Other methods employ one or more polynucleotides capable of hybridizing to a polynucleotide encoding OB-cadherin or N-cadherin.
Within certain aspects, the present invention provides methods for determining the presence or absence of a cancer in a patient, comprising the steps of: (a) contacting a biological sample obtained from a patient with a binding agent that specifically binds to OB-cadherin or N-cadherin; and (b) detecting in the sample an amount of polypeptide that binds to the binding agent, relative to a predetermined cut-off value, and therefrom determining the presence or absence of a cancer in the patient.
Within further aspects, methods are provided for monitoring the progression of a cancer in a patient, comprising the steps of: (a) contacting a biological sample obtained from a patient at a first point in time with a binding agent that specifically binds to OB-cadherin or N-cadherin; (b) detecting in the sample an amount of polypeptide that binds to the binding agent; (c) repeating steps (a) and (b) using a biological sample obtained from the patient at a subsequent point in time; and (d) comparing the amount of polypeptide detected in step (c) to the amount detected in step (b) and therefrom monitoring the progression of the cancer in the patient.
Within other aspects, methods are provided for evaluating the metastatic potential of a cancer in a patient, comprising the steps of: (a) contacting a biological sample obtained from a patient afflicted with cancer with a binding agent that specifically binds to OB-cadherin or N-cadherin; and (b) detecting in the sample an amount of polypeptide that binds to the binding agent, relative to a predetermined cut-off value, and therefrom evaluating the metastatic potential of the cancer in the patient.
Kits for determining the presence or absence of a cancer in a patient are also provided. Such kits may comprise: (a) an antibody or antigen-binding fragment thereof that specifically binds to an OB-cadherin or N-cadherin CAR sequence; and (b) a detection reagent.
The present invention further provides methods for determining the presence or absence of a metastatic cancer in a patient, comprising the steps of: (a) contacting a biological sample obtained from a patient with an oligonucleotide that hybridizes to a polynucleotide encoding OB-cadherin or N-cadherin; and (b) detecting in the sample a level of a polynucleotide that hybridizes to the oligonucleotide, relative to a predetermined cut-off value, and therefrom determining the presence or absence of a metastatic cancer in the patient. Within certain embodiments, the amount of mRNA is detected via polymerase chain reaction using, for example, at least one oligonucleotide primer that hybridizes to a polynucleotide that encodes OB-cadherin or N-cadherin, or a complement of such a polynucleotide. Within other embodiments, the amount of mRNA is detected using a hybridization technique, employing an oligonucleotide probe that hybridizes to a polynucleotide that encodes OB-cadherin or N-cadherin, or a complement of such a polynucleotide. In a preferred embodiment, at least one of the oligonucleotide primers comprises at least about 10 contiguous nucleotides of a DNA molecule encoding OB-cadherin or N-cadherin.
In related aspects, methods are provided for monitoring progression of a cancer in a patient, comprising the steps of: (a) contacting a biological sample obtained from a patient with an oligonucleotide that hybridizes to a polynucleotide encoding OB-cadherin or N-cadherin; (b) detecting in the sample an amount of polynucleotide that hybridizes to the oligonucleotide; (c) repeating steps (a) and (b) using a biological sample obtained from the patient at a subsequent point in time; and (d) comparing the amount of polynucleotide detected in step (c) with the amount detected in step (b) and therefrom monitoring progression of a cancer in the patient.
Within other aspects, methods are provided for evaluating the metastatic potential of a cancer in a patient, comprising the steps of: (a) contacting a biological sample obtained from a patient with an oligonucleotide that hybridizes to a polynucleotide encoding OB-cadherin or N-cadherin; and (b) detecting in the sample an amount of a polynucleotide that hybridizes to the oligonucleotide, relative to a predetermined cut-off value, and therefrom evaluating the metastatic potential of the cancer in the patient.
In related aspects, diagnostic kits comprising the above oligonucleotide probes or primers are provided.
These and other aspects of the present invention will become apparent upon reference to the following detailed description and attached drawings. All references disclosed herein are hereby incorporated by reference in their entirety as if each was incorporated individually.